CN104278122A

CN104278122A - Device for loading raw material for manufacturing sponge iron

Info

Publication number: CN104278122A
Application number: CN201110383677.4A
Authority: CN
Inventors: 铃木良知; 园部秋夫; 黑木隆; 阪口泰彦; 板谷宏; 三角四雄; 船津功
Original assignee: NKK Corp
Current assignee: JFE Steel Corp; JFE Engineering Corp
Priority date: 2003-01-31
Filing date: 2004-01-29
Publication date: 2015-01-14
Anticipated expiration: 2024-01-29
Also published as: SE0402286L; WO2004067784A1; CN102492797A; CN104278122B; SE528252C2; CN102492797B; US20050193862A1; SE0402286D0

Abstract

The invention relates to a device for loading raw material for manufacturing sponge iron. A method for manufacturing sponge iron and an apparatus for charging in the method are disclosed. Iron oxide powder and reducing-agent powder are charged such that alternating layers of the iron oxide powder and the reducing-agent powder are formed and such that each of the layers is in the form of a helix, and then a reduction treatment is performed. The method has not only high reaction efficiency of a gas, high quality, and high productivity, but also the advantage for a production adjustment because the amount of charge can be adjusted without the limitation of a reduction time. The molar ratio of the carbon content in the reducing agent to the oxygen content in the iron oxide in the reaction container is preferably 1.1 or more.

Description

The charging apparatus of sponge iron production of raw material for use

The application is application number is 200480000156.4 (international application no is PCT/JP2004/000866), National Phase in China enter day be on October 8th, 2004 (international filing date is on January 29th, 2004), denomination of invention is the divisional application of the Chinese patent application of " manufacture method of sponge iron and reduced iron powder, sponge iron and charging apparatus ".

Technical field

The present invention relates to using iron powder as manufacture raw material sponge iron manufacture method and use the manufacture method of reduced iron powder of the sponge iron manufactured with aforesaid method.

Above-mentioned reduced iron powder, except directly using except powder, also can use as the raw material of the sintered products of mechanical part and magneticsubstance etc.

The invention still further relates to the charging apparatus of the manufacture sponge raw material for iron of the manufacture method with above-mentioned sponge iron, and with the high purity sponge iron that this manufacture method can manufacture.

To reaction vessel charging feedstock (charge) owing to being called the filling (but being translated into charge when turning into English) of raw material traditionally, so also imitate this example in this manual, after mainly use the vocabulary such as " filling ", " tamping unit ".

Background technology

Figure 1A and Figure 1B represents the manufacture method of general sponge iron.Wherein Figure 1A is the sectional drawing representing raw material occupied state in container, and Figure 1B is its horizontal sectional view.

When manufacturing sponge iron, below can capping round shape refractory materials reaction vessel 1 (Fire-resistant cabinet) in, croci 2 and reductive agent powder 3 layering are filled to concentric(al) circles tubular, use continuous tunnel furnace etc. that each container is heated (indirect heating) to 1050 ~ 1200 DEG C.By heating in early stage, the ferric oxide 2 in above-mentioned reaction vessel 1 is reduced (slightly reducing), is sintered simultaneously, becomes spongy metal iron, namely sponge iron.

Wherein croci 2 can use rolling iron scale powder and iron ore etc. after fragmentation.In addition reductive agent powder 3 can use coke powder and coal dust etc.Lime powder etc. can be added as required in reductive agent powder 3.

Above-mentioned technology is published in the documents such as " iron and steel brief guide " the 3rd edition the 5th volume the 457th page ~ 459 pages (mainly the 457th page of right hurdle 10th ~ 13 row) and No. 2002-241822, JP.

As shown in Figure 1A, B, in existing sponge iron manufacturing technology, croci 2 is filled to be round shape (hereinafter referred to round shape iron oxide layer) in reaction vessel 1, and reductive agent powder 3 is filled and surrounds around this round shape iron oxide layer.Reductive agent powder 3 is all filled the upper and lower of this round shape iron oxide layer and center.

Its result, fills after raw material, reaction vessel 1 is heated, and first, in the initial stage, is present in the oxygen in reductive agent packing layer space and the carbon in reductive agent reacts the CO generated ₂gas, is added on the CO generated after the Wingdale in reductive agent etc. decomposes ₂there is the reaction of (1) formula in the carbon in gas and reductive agent, generates the CO of reducing gas at the packing layer (reductant layer) of reductive agent powder 3.

C+CO ₂→ 2CO ... (1) formula

And the CO gas generated like this arrives the packing layer (iron oxide layer) of croci 2 from reductant layer, by the reaction of following (2) formula, by iron oxide reduction, produce CO ₂(carbonic acid gas) gas.

FeOn+nCO → Fe+nCO ₂(2) formula

In addition, this CO ₂a gas part is diffused in the iron oxide layer be reduced, then arrives reductant layer, in this layer, by the reaction of (1) formula, carbon is become CO.And this CO gas generated is diffused into iron oxide layer again, the reaction that (2) formula occurs with unreduced ferric oxide generates iron, generates CO simultaneously ₂gas.

Its result, the croci 2 be filled in above-mentioned reaction vessel 1 passes through repeatedly to carry out within a certain period of time the reaction of (1) formula and (2) formula, and Restore All becomes iron powder.While this external reduction reaction therewith, the iron be reduced also sinters to each other, becomes columnar sponge iron (sintered compact).The face shaping (bottom omission) of the sponge iron that Fig. 2 expression prior art obtains.

The amount of the CO gas that ferric oxide Restore All wherein will be made to need viewed from (2) formula in theory mol ratio (mole number of the Sauerstoffatom in the mole number/ferric oxide of the carbon atom=CO gas) be 1.The amount mol ratio (mole number of the Sauerstoffatom in the mole number/ferric oxide of the carbon atom in=reductive agent) of the reductive agent that ferric oxide Restore All therefore will be made to need is 1.0.Below the mole number of the Sauerstoffatom in the mole number/ferric oxide of the carbon atom in reductive agent is called " carbon amounts/oxygen amount (mol ratio) ".

In above-mentioned method of reducing, think in reaction vessel 1 generate CO gas and CO ₂gas is determine that reduction reaction carries out the principal element of speed to the diffusion in the layer of croci 2 and reductive agent powder 3.But, in the method for the acquisition interstitital texture shown in Fig. 1, there is CO and CO ₂the diffusion length of gas is large, the problem that reduction required time is long.

Reduction needs words for a long time, such as carry out in the production process of the commercial production scale heated at use continuous tunnel furnace, reaction efficiency (gas utilization efficiency) can be caused to reduce, and being filled into taking-up goods from raw material needs a couple of days, is related to the reduction of productivity.Moreover, the energy expenditure of the heating required for reduction also significantly increases.

Namely in the filling mode such as shown in Figure 1A, B, the amount of the sponge iron of manufacture be increased, the thickness of croci 2 (radial direction) must be thickened, so the recovery time is elongated.Perhaps can say, shorten the recovery time, thinning for the thickness of croci 2, the sponge iron that can manufacture due to each reaction vessel 1 reduces, and may not necessarily improve the output of unit time.

Therefore Problems existing is, first will determine (uniquely) thickness of croci 2 that turnout is maximum and the combination of recovery time, not only turnout is restricted, and the degree of freedom of adjustment output is also little.

In addition, in the filling mode that Figure 1A, B are such, the CO gas generated in above-mentioned reaction has a side of 3 layers, the reductive agent powder flowing through density lower level, has the tendency gone to outside reaction vessel 1.Therefore CO gas can not contribute to effectively carrying out reduction reaction.

Between reaction vessel 1 and croci 2, superfluous reductive agent powder 3 must be filled with the inner side of round shape iron oxide layer, make not collapse at the layer of sintering stage oxidation iron powder 2.

Because of above-mentioned situation, in existing method, have reductive agent powder 3 must more than mol ratio 2.0, the problem of the per unit area yield consumption deterioration of reductive agent.

In addition the bottom of round shape iron oxide layer swells because of deadweight.Therefore, swollen most iron oxide reduction within the predetermined recovery time is also had fully not carry out, the remaining problem having responseless part.

The object of the invention is the above-mentioned various problem being conducive to solving prior art existence.The object of namely the present invention is, the manufacture method of sponge iron of the output that proposes easily to boost productivity, adjust.

The device of filling raw material in reaction vessel easy to use when another object of the present invention is to propose to state manufacture method on the implementation.

Summary of the invention

The present inventor continues the result of wholwe-hearted research, finds, by croci and the reductive agent powder mode be filled in reaction vessel are thought a little way, can effectively solve above-mentioned problem, complete the present invention.

Namely the 1st scheme of the present invention is a kind of manufacture method of sponge iron, there is filling work procedure croci and reductive agent powder be filled in reaction vessel, from above-mentioned reaction vessel external heat, make the above-mentioned croci reduction (slightly reducing) in above-mentioned reaction vessel, make the reduction operation of sponge iron in lump form, in above-mentioned filling work procedure, fill above-mentioned croci and above-mentioned reductive agent powder, be piled into layer that is interlaced and helically.

In above-mentioned 1st scheme, also can in following (1) ~ (8) more than 1 or 2 be applicable to condition arbitrary combination adopted.

(1) in above-mentioned filling work procedure, container side (being called outer peripheral portion) in above-mentioned reaction vessel and vertical centre shaft portion form the layer be made up of reductive agent powder, are filled to the layer of above-mentioned interlaced and helically at the rest part (being called middle portion) except this layer simultaneously.Divide at the plane sectional drawing upper peripheral edge portion of container, central axis portion respectively corresponding peripheral part, centre portions.Middle portion wishes to make round shape or cylindrical.In addition reaction vessel is in columnar situation, and so-called vertical centre shaft portion is the axial portions of this cylinder.

(2) above-mentioned croci uses the powder selecting at least one from the oxide skin of iron ore, rolling and the brown iron oxide that reclaims from spent pickle liquor.

(3) above-mentioned reductive agent powder uses and at least select a kind of powder from coke, charcoal and coal.

(4) in above-mentioned reductive agent powder, add carbonic acid gas generate source.Carbonic acid gas generates source and is particularly suitable for using Wingdale (comprising white lime).The reductive agent powder of in this case filling in addition is called the material adding in reductive agent powder and mix after carbonic acid gas generates source power.

(5) above-mentioned Heating temperature in above-mentioned reduction operation more than 1000 DEG C less than 1300 DEG C is made.

(6) in above-mentioned filling work procedure, form spiral-shaped layers, the thickness of the layer of controlled oxidization iron powder and the layer of reductive agent powder can change.Wherein so-calledly control to change to comprise: in each reaction vessel, at least can set different thickness in certain layer, and the implication in two that position in 1 reaction vessel at least can make the thickness of certain layer change.

(7) in above-mentioned filling work procedure, the amount of the amount of the above-mentioned croci in above-mentioned reaction vessel and above-mentioned reductive agent powder be controlled to carbon amounts contained in above-mentioned reductive agent powder relative to above-mentioned croci in contained oxygen amount mol ratio more than 1.1.Wherein wish that mol ratio is more than 1.15, more wish that mol ratio is more than 1.2.

(8) in the filling work procedure meeting above-mentioned (1) and (7), the above-mentioned croci amount be filled in the part of stratiform and above-mentioned reductive agent amount of powder are controlled to carbon amounts contained in above-mentioned reductive agent powder relative to being contained in the mol ratio of oxygen amount contained in above-mentioned croci more than 0.5.Wherein so-called " being filled to the part of stratiform " refers to the cylindrical area being piled into spiral croci and reductive agent powder bed, is generally equivalent to the part from whole each " layer that reductive agent powder be made up of " of filled band removing described in (1).

2nd scheme of the present invention is a kind of manufacture method of reduced iron powder, and reduction after the sponge iron manufactured by the 1st scheme of the present invention is pulverized (essence reduction), then pulverizes.

Go for the arbitrary combination being applicable to condition (1) ~ (8) in the 1st invention of the present invention.

3rd scheme of the present invention is the sponge iron sintering spiral (helix) shape block into, and desirably metal Ferrum content is the highly purified sponge iron of more than 97 quality %.Highly purified sponge iron in the 1st scheme of the present invention, such as, is useful in the reduction treatment of applicable condition (7) by the sufficient time, can manufactures the sponge iron in lump form of more than weight 100kg.

4th scheme of the present invention is the tamping unit manufacturing sponge raw material for iron, it is the tamping unit of filling croci and reductive agent powder in container, have and be inserted in said vesse, the insertion portion that can rotate and move up and down in container and be arranged on above-mentioned insertion portion lower end, the croci relief outlet that can rotate together with above-mentioned insertion portion and reductive agent relief outlet.

4th scheme of the present invention is in the method for the manufacture sponge iron of the 1st scheme of the present invention, is suitable for, in reaction vessel, above-mentioned croci and above-mentioned reductive agent powder are filled to layer that is alternately mutual and curl.

In the 4th scheme of the present invention, wish that the port area of above-mentioned croci relief outlet and above-mentioned reductive agent powder discharge port can change.In the 1st scheme of the present invention, such structure may be used for the situation particularly meeting applicable condition (6).

In addition, in the 4th scheme of the present invention, the end portion that the part of above-mentioned insertion portion has cylindrical-shaped main body part that its diameter is less than 85% of said vesse internal diameter and its diameter to be the horizontal section of 90 ~ 95% of said vesse internal diameter be circular cylinder is formed, and wish that the horizontal section shape of above-mentioned end portion is the fan-shaped of center containing above-mentioned circle and part-circular periphery, or comprise this fan-shaped shape.In the 1st scheme of the present invention, such structure is applicable to the object forming thin reductive agent powder bed at peripheral part described in applicable condition (1).Even if generate the projection of dirt settling in this external reaction vessel, also can not produce interference to it, above-mentioned insertion portion can be inserted in reaction vessel.

Accompanying drawing explanation

Figure 1A is the sectional drawing that existing croci and reductive agent powder filling mode are described.

Figure 1B is the horizontal sectional view of the IB-IB ' section representing Figure 1A.

Fig. 2 is the skeleton view representing the sponge iron face shaping obtained by existing method.

Fig. 3 A is the sectional drawing of an example of the filling mode that croci of the present invention and reductive agent powder are described.

Fig. 3 B is the horizontal sectional view of the IIIB-IIIB ' section representing Fig. 3 A.

Fig. 4 A is the sketch of the example representing insertion portion of the present invention (rotate and load cylinder) structure.

Fig. 4 B is the sectional drawing of the occupied state in the rotation loading cylinder situation of expression use Fig. 4 A.

Fig. 5 is for representing the sketch of another example of insertion portion of the present invention (rotate and load cylinder) structure.

Fig. 6 is the sectional drawing of another example of the filling mode that croci of the present invention and reductive agent powder are described.

Fig. 7 is the skeleton view of the sponge iron face shaping that expression the present invention obtains.

Fig. 8 illustrates sectional drawing croci and reductive agent powder level being piled into the test example of the filling mode of multilayer.

Fig. 9 represents for several different ferric oxide thickness, the diagram of recovery time (longitudinal axis) relation of carbon amounts/oxygen amount (mol ratio) (transverse axis) and needs in the whole reaction vessel of mutual alternately filling mode.

Figure 10 illustrates sectional drawing croci and reductive agent powder level being piled into another test example of the filling mode of multilayer.

Figure 11 is for representing for several different ferric oxide thickness, and another replaces mutual carbon amounts/oxygen amount (mol ratio) (transverse axis) that replace filling part of filling mode and the diagram of recovery time (longitudinal axis) relation needed mutually.

Figure 12 for representing for several different ferric oxide thickness, the diagram of carbon amounts/oxygen amount (mol ratio) (transverse axis) in the whole reaction vessel of another alternately filling mode mutually and recovery time (longitudinal axis) relation of needs.

Figure 13 is that expression volution replaces filling (section line) mutually and round shape is filled (blank) middle ferric oxide increasing amount (% weight, transverse axis) and passed through the diagram of metallic iron purity (quality %, the longitudinal axis) relation that reduction obtains.

Figure 14 A is the sectional drawing of another example representing insertion portion of the present invention (rotate and load cylinder) structure.

Figure 14 B is the direction view (wall thickness omission) of the XIVB-XIVB ' section representing Figure 14 A.

Embodiment

[fill method of raw material and tamping unit]

The method that the present invention is filling raw material in reaction vessel has its feature.Its Raw is croci and reductive agent powder, also Wingdale etc. can be added together with above-mentioned reductive agent as required.

Namely, prior art method as shown in Figure 1, such as, adopt in the reaction vessel 1 of vertical and cylindrical refractory materials, vertically croci 2 and reductive agent powder 3 be filled to the method for circular concentric.Replace aforesaid method in the present invention, croci and reductive agent powder are filled to mutually alternately and all helically, namely adopt and be filled to the method that structure that both pile up in container is the laminated arrangement (below become " volution is alternately filled mutually ") that the spiral layers of croci and the spiral layers of reductive agent powder replace mutually.

Adopt volution mutually to replace completion method, croci and reductive agent powder are filled simultaneously, and can carry out continuously.Therefore the thickness (loading level) of each layer can be made certain.Therefore, the Thickness Ratio of reductant layer and iron oxide layer can keep certain.This Thickness ratio can set arbitrary ratio according to object and situation in each reaction vessel.

On the other hand, Thickness ratio also can change arbitrarily and at any time in charging.

Therefore, volution replaces completion method is mutually the method going far towards to improve productivity and improve output.

Fig. 3 A, Fig. 3 B represent an example of the present invention.Wish that raw material of the present invention is filled uses device for charging material 14 croci 12 and reductive agent powder 12 to be loaded simultaneously, is filled in the columnar reaction vessel 11 (Fire-resistant cabinet) of the refractory materials formations such as SiC.

Wish that the structure of device for charging material 14 is as follows.

It is main formation that device for charging material 14 loads cylinder 14b (loading part) with the rotation in insertion reaction container 11.The axle side rotating the tubular body loading cylinder 14b is divided into 2 parts with central dividing plate 14a, namely can load croci 12 and reductive agent powder 13 (powder in each storage part is not shown) in croci storage part 17 and reductive agent powder storage part 18 in the space be separated.In addition, be provided with and correspond respectively to the croci relief outlet 15 of storage part 17,18 and the opening portion of reductive agent powder discharge port 16 rotating the lower end (lower end or lower end) loading cylinder 14b.Although not shown, (such as open height a), namely wishes the area that can adjust opening to wish can to adjust opening degree by the gate of each relief outlet slide gate.The position of relief outlet and towards determining as required, can using rotate load cylinder 14b bottom surface, side or be located at the otch on bottom surface etc. arbitrary face as opening portion.In principle, the discharge of each raw material powder wishes to utilize the deadweight of the raw material powder being contained in storage part to carry out (discharge).

Fig. 4 A represents that above-mentioned rotation loads the diagram of an example of the details drawing of cylinder 14b.In this example, the square tube shape lower end extended position of cylinder is provided with perpendicular to dividing plate 14a is outstanding draws off part 14c.Draw off in part 14c the relief outlet (opening) 15,16 being provided with on the sidewall at diagonal angle and being connected with above-mentioned storage part 17,18.Such rotation is used to load the sectional drawing of filling work procedure in cylinder situation as shown in Figure 4 B.

As its a kind of version, the horizontal section shape that part and reductive agent powder draw off part of drawing off of croci can be considered to be in diagonal angle setting with substantially the fan-shaped of 1/4th circles respectively.In this case, can be arranged at least partially in 2 relief outlets 15,16 be equivalent to fan-shaped straight line portion side at grade, be clipped in the axis both sides (becoming the sectional state of Fig. 3) rotating and load cylinder 14b.

Fig. 5 represents that above-mentioned rotation loads the auspicious figure of another example of cylinder 14b.

In order to the raw material powder reliably controlling to load spreads all over the circumferential location of reaction vessel 11, it is desirable to make the diameter of rotation loading cylinder 14b (particularly its lower end) to be the value of the internal diameter close to reaction vessel 11.Due to reaction vessel Reusability, and sometimes using after the stacking part of multiple cylinder as reaction vessel, be attached in reaction vessel so the ash in the iron be reduced and reductive agent grades, form projection.In addition, due to the distortion that Reusability produces, container also has some to tilt.Therefore the internal diameter rotating the lower end and reaction vessel 11 loading cylinder 14b just matches, and when loading rotation and loading cylinder 14b, likely causes and contacts with reaction vessel 11, cause breakage.

The lower end diameter making rotation load cylinder 14b is the openings guaranteeing near from reaction vessel immediate vicinity to circumference at each relief outlet close to the object of the internal diameter of reaction vessel 11.The words of therefore making an effort on the position of relief outlet, the horizontal section shape that there is no need to make rotation to load the lower end of cylinder 14b becomes circular completely, is that the fan-shaped of a part for this circle (imaginary circle) or at least inner words comprising this fan-shaped shape are just passable.

Fig. 5 is made fan-shaped example lower end, and croci relief outlet 15 and reductive agent powder 16 are configured to unsymmetrical.Wherein, croci relief outlet 15 and reductive agent powder 16 are arranged on the side (be equivalent to the position of scallop) that draw off part 14c identical with Fig. 4.Further, drawing off the bottom surface also opening of part 14c, but the powder piled up instead of bottom surface, and each powder 12,13 is mainly discharged from the side.19a, 19b are suppressing plate.

Fan-shaped central angle can be arbitrary, ites is desirable to about 180 ° (namely semicircle) or less to make lower end enough compact.Also wish, the maximum diameter drawing off the horizontal section shape of part is less than imaginary circular diameter.

In addition, from the viewpoint of productivity, the internal diameter of lower end imaginary circle diameter more close to reaction vessel is better, wishes at about more than 90% of reaction vessel internal diameter.On the other hand from the viewpoint of processing property, it is desirable to suitably to reduce imaginary circular diameter, wish at about less than 95% of reaction vessel internal diameter.

In addition, wish that the main diameter making to be rotatably inserted into a 14b is about less than 85% of reaction vessel internal diameter, guarantee the leeway moved horizontally in container, avoid contact.In addition, from the viewpoint of carrying path guaranteeing the raw material powder loaded, wish that main diameter is about more than 30% of reaction vessel internal diameter.

Use such device for charging material 14, raw material is filled to the volution mutually replaced, adjust the port area (opening degree) of above-mentioned relief outlet 15,16, above-mentioned rotation is loaded cylinder 14b and inserts in above-mentioned reaction vessel 11 from top.Loading cylinder 14b (therefore making relief outlet 15,16) rotation limit, limit by making above-mentioned rotation to promote with certain speed, iron oxide layer and reductant layer can be made mutually to be wound in volution with certain ratio and filled (mutually alternately filling) by this relief outlet.Formed together with reductive agent powder 13 in reaction vessel 11 internal oxidition iron powder 12 like this and be mutually piled into spiral packing layer alternately.

To each storage part 17,18 charging feedstock, can as required, carry out before filling to reaction vessel or in filling.

Fig. 6 is another example representing fill method of the present invention.Wherein device for charging material 14 simply represents.

As shown in Figure 6, when raw material powder is filled in reaction vessel, the position that volution also can be made mutually alternately to fill is limited to the region except the periphery of the axis along cylindrical reaction vessel 11.In addition, the position that volution also can be made mutually alternately to fill is in except along the region except the axial axle center part of reaction vessel 11.In addition, the position that volution also can be made mutually alternately to fill is in except along the region except the axial axle center of reaction vessel 11 and periphery two portions.In various situation, the region that volution is alternately filled mutually is all called cylindrical medial part.There are outer peripheral portion, axial portions again on the plane sectional drawing of container, are equivalent to peripheral part and centre portions respectively.

From preventing the rotation of device for charging material 14 from loading part 14b and reaction vessel 11 viewpoint disturbed and the sintering viewpoint preventing croci and reaction vessel contact part, sometimes have no alternative but the reductant layer being provided with above-mentioned outer peripheral portion.In addition, the reductant layer of above-mentioned axial portions is sometimes set because of the facility in manipulation when taking out sponge iron from container., only there is reductant layer in periphery or axial portions, the path of forming reactions gas, therefore, the gas diffusion in reaction vessel is smooth and easy and even, also can expect the effect having and improve reduction reaction speed.In addition, when periphery is made up of reductant layer, the outer wall deposition to goods can also be prevented.Therefore, wish as required, the yield rate of consideration reductive agent and carbon amounts/oxygen amount (mol ratio) etc., make thickness (radial direction) suitable, arrange these reductant layers.

When cylindrical vessel, it is suitable for making outer peripheral portion be the thickness (radial direction) of about more than 2.5%, less than 5% of inside diameter of vessel (diameter of inner face).Wish that the diameter of axial portions is about below 250mm on the other hand.

Such as, reductant layer to be formed in periphery, be provided with opening in the side rotating loading cylinder 14b, from then on can discharge the reductive agent powder forming outer peripheral portion by opening.In addition, will form reductant layer in axial portions, in Fig. 4 etc., be provided with the position of central dividing plate 14a, also forming Central barrel section, the lower end of heart cylinder part is provided with opening hereinto, from then on can discharge the reductive agent powder forming axial portions by opening.

These openings can be connected with the relief outlet 16 for the formation of spiral layers, also can be used alone.

Figure 14 A represents that the rotation can carrying out the filling of Fig. 6 loads an example of cylinder.Figure 14 B is the sectional drawing of the XIVB-XIVB ' position of Figure 14 A.(in order to simplify, eliminating the thickness of wall).In this example, the bottom surface rotating loading cylinder 14b is provided with the alternately filling reductive agent powder discharge port 16 rotating alternately filling etc.In addition, be provided with opening in the lower side rotating loading cylinder 14b, form towards the reductive agent powder discharge port 16a of periphery.There is the shaft core position bottom surface rotating loading cylinder 14b to be provided with towards the reductive agent powder discharge port 16b in axle center again, utilizing central dividing plate 14d to guide a part of reductive agent powder.

As shown in Figure 3A, generally in order to ensure nethermost iron oxide layer reduction and prevent the sintering of iron oxide layer and reaction vessel, it is desirable to only to form reductive agent powder (with Wingdale etc.) layer at orlop.Wish in the superiors it is equally also only form reductive agent powder bed.In above-mentioned raw materials charging apparatus 14, utilizing to close croci relief outlet 15 (opening degree is zero) or stop loading cylinder 14b to rotation provides the methods such as croci can form these reductant layers.

In the present invention, use said apparatus carry out volution alternately fill time, wishing can the thickness of control break iron oxide layer and reductant layer.In a reaction vessel, namely wish that the thickness of each layer may be controlled to necessarily, such as, wish suitably to adjust thickness according to the difference of raw material.

Such as, by above-mentioned rotation is loaded to the some of the opening degree of the speed of rotation of cylinder 14b, lift velocity and above-mentioned relief outlet 15,16 or more than 2 adjust, this change of thickness can be realized.Especially, by controlling the opening degree of relief outlet 15,16 to the opening and closing of gate, gas diffusion resistance can not be caused to increase and recovery time prolongation, output can not be caused to reduce, can guarantee that the basis of stable operation realizes, so be desirable method.

In theory, vertical response container 11 short transverse such as near bottom, middle part, top can continuously or be interrupted change thickness, the present invention does not get rid of such use-pattern.Such as on the top there is reduction reaction carrying out fast tendency, can consider to increase the use-pattern of the thickness of iron oxide layer etc.

In addition the thickness being piled into spiral oxide skin and reductant layer wishes each layer about more than 5mm, both each 1 layer with about more than 10mm.More wish at more than 40mm.Thickness is excessively thin, and the fluctuation due to thickness easily produces unstable part.The each layer of the lower limit of wishing about more than 10mm, each 1 layer with about more than 30mm.

On the other hand, thickness is blocked up, and due to the reduction of the increase and raw material efficiency that can cause the reduction treatment time, wish that each layer is about below 100mm, each 1 layer of sum is about below 200mm.The each layer of the upper limit of wishing is about below 80mm, and each 1 layer of sum is about below 150mm.

The thickness of iron oxide layer and reductant layer is not generally with thickness, but represents by carbon amounts/oxygen amount (mol ratio).To introduce below about suitable ratio.

Device for charging material described above is an example, its structure mainly contains the insertion portion that can move up and down and rotate, and the relief outlet of croci and reductive agent powder is provided with at this insertion portion, to rotate while insertion portion therewith rotates and mobile, by being inserted in reaction vessel, this rotation limit, insertion portion limit being promoted, becoming dual volution to fill with reductive agent powder accumulation croci from above-mentioned relief outlet.

Such as, the round shape of insertion portion is favourable, but is not limited thereto.Such as according to the shape of reaction vessel, section form can be the cylinder of the shapes such as fan-shaped, star, cosmos.In addition, storage part need not make dividing plate, and shape and position are also arbitrary.It is identical that croci storage part and reductive agent powder storage part there is no need volume.

At the periphery of relief outlet 15 and 16 in order to guide the raw material powder of filling from relief outlet to target direction, suitable fixing or movable guide plate, suppressing plate etc. are set.

[raw material powder]

In sponge iron manufacture method of the present invention, the raw material be filled in reaction vessel must have croci and reductive agent powder at least, wishes that croci uses the powder that iron ore or the oxide skin of rolling that produces in the hot-rolled process of steel are made.The acid of this external application hydrochloric acid etc. is removed the oxide compound of steel surface etc. or in pickling process, is produced spent acid (spent pickle liquor), and the croci that these spent pickle liquor roastings etc. obtain also can be used as croci.The median size be applicable to of these crocis is about 0.05mm ~ 10mm.

Wish than above-mentioned thinner croci, such as specific surface area at 2m ²industrial more than 0.01 μm of/more than g and granularity can control the hematite powder of particle diameter etc. and be blended in the powder such as oxide skin and iron ore of the rolling and use, and makes the Quality advance of sponge iron.

Reductive agent powder uses the carbonaceous powder of carbon containing.Coke powder, charcoal (one of high volatile volatile charcoal), coal dust (desirably cohesionless), hard coal powder, charcoal powder etc. are suitable as carbonaceous powder and use.There is the viewpoint from reduction efficiency again, wish that carbon content in carbonaceous powder is more than 60%.The median size that reductive agent powder is suitable for also is about 0.05mm ~ 10mm.

Mix as reductive agent powder the powder adding carbon dioxide generation source as required to use also without any problem as the part forming reductant layer.Preferably use the generation source of powder as carbon dioxide of Wingdale (comprising white lime).

[reduction operation]

These crocis 12 and reductive agent powder 13 (comprise and add mixing carbon dioxide gas body generation source power) are alternately filled in above-mentioned reaction vessel 11 by device for charging material 14 helically Fig. 3 A, B etc. Suo Shi.Reaction vessel 11 wishes to use the reaction vessel being such as called the columnar SiC of Fire-resistant cabinet.The shape of reaction vessel 11 does not limit, but thinks that round shape is best.In addition the size of reaction vessel also has no particular limits, but in columnar situation, the cross section diameter of its inner face is about about 200mm ~ 800mm, highly about about 100mm ~ 2000mm scope is suitable.To wish by the weight of the sponge iron blocks of a vessel fabrication, at about more than 10kg, from the viewpoint of productivity, to it is desirable to, at about more than 50kg, more to wish at about more than 100kg.

Then, the above-mentioned reaction vessel 11 being filled with croci 12, reductive agent powder 13 and the Wingdale that uses as required etc. is loaded in the sintering oven of continuous tunnel furnace etc. under the state on chassis etc. being placed on, the raw material be filled in container will by the time for reducing of heating regulation together with container, this reduction is called as thick reduction, the purity that requires (metallic iron account for reduction after the content of sponge iron) depends on the purposes of reduced iron powder, but at least at more than about 90 quality %, more than the about 97 quality % of high purity applications to be required.The target value of purity does not have the upper limit, but present situation, the purity that can reach in cost allowed band is maximum is about about 99.5mass%.

The above-mentioned Heating temperature for reducing is inadequate, and the reduction of ferric oxide can not fully be carried out, the purity drop of sponge iron.Wish that the lower limit of Heating temperature is about 1000 DEG C.On the other hand, Heating temperature is too high, with reduce the sintering of sponge iron simultaneously carried out can excessively, sponge iron is hardening, worries that the power consumption of the coarse breaking caused subsequently increases, and causes manufacturing cost to increase with the loss of breaking tool.Wish that the upper limit of Heating temperature is 1300 DEG C.The Heating temperature of therefore wishing is 1000 ~ 1300 DEG C of scopes.

When continuous tunnel furnace is used as sintering oven, to be placed on chassis and the above-mentioned reaction vessel 1 (with the ferric oxide of its inside) of movement in this sintering oven can first to need the preheat zone that increased gradually by temperature with 24 hours (suitable scope is more than 20 hours, less than 28 hours), then the sintering zone of about 1000 DEG C ~ about 1300 DEG C keep 60 hours (applicable scope be more than 36 hours best more than 56 hours, in addition will below 72 hours, preferably below 64 hours).After this, through the cooling zone (being suitable for passing through with 20 hours ~ 28 hours) that excess temperature reduces gradually, reduction treatment is completed.From the viewpoint of protective reaction container (refractory materials) etc.; wish the outlet side temperature of the inlet side temperature of preheat zone and cooling zone is about 200 DEG C (about 20 DEG C ~ 400 DEG C), the outlet side temperature of preheat zone and the inlet side temperature of cooling zone are about 900 DEG C (sintering zone temperature-450 DEG C ~ sintering zone temperature about-50 DEG C).

Heat by this reduction reaction caused, ferric oxide is reduced agent reduction, becomes block sponge iron.Certainly the sponge iron obtained is spiral piece.Fig. 7 represents an example (top and bottom are omitted) of the sponge iron face shaping obtained by method of the present invention.

The height (axis) of the sponge iron blocks obtained is more high better, but considers the restriction by reaction vessel size, and when the height of reaction vessel is increased, sintering oven becomes large, causes thermo-efficiency to reduce, so wish that size is at below 2000mm.

Adopt method of the present invention can obtain the above high purity sponge iron of purity 97 quality %.When purity at more than 97 quality %, the characteristic of the product of the sintered component being conducive to ensureing mechanical part and magneticsubstance etc. or the reduced iron powder directly using powder.But method of the present invention, also has advantage except purity, make purity more than 97 quality %'s or high purity sponge iron manufacture method so do not limit.Namely, the general thick reduction of more than purity 90 quality % can be all applicable to.In addition, except metallic iron composition, general containing ferriferous oxide and the impurity (Si, Mn, P, S etc.) amounting to below 1 quality %.

Take out from reaction vessel 11 after the sponge iron that the heating of thick reduction generates afterwards is separated with reductive agent.The sponge iron taken out from reaction vessel 11 is in order to carry out essence reduction again, and general coarse breaking extremely less than about 150 μm, makes and slightly reduce particle.Then, this slightly reduces particle and is loaded in the fine reduction furnace of reducing atmosphere and carries out essence reduction, then becomes reduced iron powder after fragmentation.

[ratio of ferric oxide and reductive agent]

When raw material is filled in reaction vessel, carry out the ratio of oxidation iron when above-mentioned volution is alternately filled and reduction dosage (solid reductant), particularly relative to the ratio of the carbon content in the reductive agent of the oxygen level needs in ferric oxide, describe together with above-mentioned (2) formula.The namely reduction reaction of the ferric oxide degree (carbon amounts/oxygen amount (mol ratio)=1.0) of carrying out after being decided by 1 C atom in reductive agent and 1 O atomic reaction in ferric oxide., general reductive agent needs the carbon amounts more than oxygen amount in ferric oxide.In existing method, owing to introducing, be pre-charged with superfluous reductive agent, be filled with the reductive agent (carbon amounts/oxygen amount (mol ratio)=2.0 ~ 2.5) of 2.0 ~ 2.5 times.In this case reduction ratio (purity of the sponge iron of requirement) metallic iron, at more than 90 quality %, is wished at more than 97 quality %.

The relation of recovery time that volution of the present invention replaces carbon amounts/oxygen amount (mol ratio) in filling mode and needs with following experimental study such as the present inventor.

As shown in Figure 8, not in test volution to simplify, have employed the mode that level is alternately filled, be alternately filled to the layer (iron oxide layer) of croci 12 and the layer (reductant layer) of reductive agent powder that general horizontal fills.The level alternately sponge iron of filling owing to obtaining through reduction is multiple circular plate type, troublesome poeration, when physical device uses, volution replaces filling and will get well, but in carbon amounts/oxygen amount (mol ratio) with carry out in the relation of reduction reaction, it is identical for alternately filling with volution.Below volution alternately to be filled and level replaces filling and is referred to as alternately filling.

The internal diameter of the reaction vessel used in test is 370mm, and the height of filling is 1400mm.In addition, croci and reductive agent powder employ the material identical with embodiment 1 described later.Reduction treatment is carried out when top temperature is 1150 DEG C.Recovery time refers to the time kept in this top temperature.

Fig. 9 represents to replace in filling mode in multiple levels that iron oxide layer thickness is different, and in ferric oxide, carbon amounts is to (mol ratio) of oxygen amount and the curve of relation of recovery time of sponge iron needs that will obtain 97 quality % iron (metallic iron).Above-mentioned mol ratio is the ratio of all ferric oxide and Restore All agent in container.

In fig .9, use now methodical round shape filling mode (Fig. 1), carry out the result of same reduction treatment an example round dot (conventional example: ●) represent.This existing method makes the thickness of iron oxide layer be 55mm, and make carbon amounts/oxygen amount (mol ratio) be 2.2, the recovery time needs 53 hours.

On the other hand, alternately fill (Fig. 8) by stratiform and carry out reduction test to when making the thickness of iron oxide layer be 15mm (test example 4: × shape marks), 20mm (test example 3: triangular marker ▲), 30mm (test example 2: square marks (■)), 50mm (test example 1: diamond indicia (◆)) respectively, its result, by making the reduced thickness of iron oxide layer, the time of reduction can be made to shorten.In addition, when more than thickness 2.0mm, above-mentioned mol ratio is more than 1.2, and the recovery time is almost certain, as existing method, need not will guarantee that mol ratio is more than 2.0.

When above-mentioned mol ratio is less than 1.2, there is elongated tendency the recovery time, but round shape filling mode is changed over (spiral), and alternately filling mode and the effect that reduces thickness exceed above-mentioned tendency.Namely because spiral way can fill ferric oxide more, such as in this example, the ferric oxide with the identical amount of round shape filling mode of conventional example can almost be filled with the turn of the screw filling mode of ferric oxide thickness 30mm.Therefore, be the effect that mol ratio more than 1.1 region fully can obtain the application in trial stretch.In addition, if mol ratio is more than 1.15, the degree increased due to the recovery time is smaller, and the words more than 1.15 are more effective.Certainly, the effect shortening the recovery time can more be obtained mol ratio is more than 1.2.

When iron oxide layer thickness is 15mm, mol ratio is more than 1.6, and its recovery time is almost certain.Further change condition, tests repeatedly, its result, has also got clear when ferric oxide thickness is less than 20mm, and following relation is set up.

Mol ratio × iron oxide layer thickness (mm)=2.3 ~ 2.5 ... (3) formula

When the thickness of iron oxide layer is less than 20mm, if by filling by the mode meeting above-mentioned (3) formula, determine the words of the thickness of iron oxide layer, singlely can determine the recovery time, stable operation, in addition, the quality of the sponge iron obtained also is stablized.But this relation is owing to being the relation based on speed of response in essence, and the thinning reason that may become thickness difficult management of reductant layer, while the raising of the layer thickness control that therefore waits in expectation technology, alleviates above-mentioned restriction.

From the viewpoint of reductive agent qualification rate, it is desirable to not increase carbon amounts/oxygen amount (mol ratio).Mol ratio is less than 2.0, has advantage, wish below 1.8 compared with existing round shape filling mode.

As shown in Figure 6, position, periphery in container or axis part are provided with reductant layer, only specify carbon amounts/oxygen amount (mol ratio) overall in container, whether the Thickness ratio of reductant layer and iron oxide layer is abundant as the target of design, and the present inventor etc. think and are necessary to study.

So the present inventor etc. are to using the Thickness ratio of the reductive agent requirement of stockpile lamination part (columnar middle portion) in reaction vessel as ferric oxide and reductive agent, whether can find that what variation tendency reduction act has carried out experimental study.

The following describes this test and result thereof.

Namely, make be filled into the carbon amounts in the reductive agent in reaction vessel to ferric oxide in the mol ratio of oxygen amount be fixed as 1.2, the reductive agent part in (position, periphery) and axle centre near reactor vessel wall is taken out, both stratiform accumulation portions so-called is divided and to have carried out changing in reductive agent carbon amounts to the test of oxygen amount in ferric oxide.

Test identical with above-mentioned test, substitute with horizontal filling mode and use.Figure 10 represents the sectional schematic diagram of the filling mode that test uses.Cover the above and below reductant layer of cylindrical medial part, be also included in its middle portion.Raw material is identical with test above with test conditions.

Figure 11 represents the recovery time change diagram for the carbon amounts/oxygen amount (mol ratio) of different several ferric oxide thickness.Round dot (●) in figure is the value in use Fig. 8 stacked system situation of the reductant layer not establishing position, periphery and axis part.

As shown in figure 11, make that the thickness of iron oxide layer is 60mm (test example 11: diamond indicia (◆)), 50mm (test example 12: square marks (■)), 4 standards of 30mm (test example 13: triangular marker ▲), 20mm (test example 14: × shape marks) reduce.Its result can be found out, utilize and make that iron oxide layer is thinning can make the recovery time shorten, and carbon amounts/oxygen amount (mol ratio) is more than 0.5, the recovery time is almost certain, but when being less than 0.5 the recovery time elongated.

Therefore, can find out, in order to guarantee carbon amounts/oxygen amount (mol ratio) effect more than 1.2 of integral container to greatest extent, wish that the carbon amounts/oxygen amount (mol ratio) of the above-mentioned cylindrical medial part making spiral packing layer part (alternately filling part) is more than 0.5.

In order to confirm this point, making the mol ratio of carbon amounts to the oxygen amount in ferric oxide in the reductive agent of above-mentioned cylindrical medial part be fixed as 0.8, having carried out changing the test being filled in the axial portions of reaction vessel and the reduction dosage of outer peripheral portion.About the result of test, in fig. 12, represent with the change curve of recovery time relative to the total carbon/whole oxygen amount (mol ratio) of the filling of reaction vessel entirety.The plate that label used is identical with Figure 11 is former corresponding.

As can be seen from Figure 12, the mol ratio of carbon amounts/oxygen amount overall in reaction vessel is more than 1.2, and the recovery time almost immobilizes, and when being less than 1.2, the recovery time is elongated.

But, as already described, even if be less than 1.2, more than 1.1, wish more than 1.15, also can fully obtain effect of the present invention.

In a word, in the present invention, when in reaction vessel 11, alternately stratiform fills (volution is alternately filled) ferric oxide and reductive agent, the ferric oxide making these raw materials overall in the reaction vessel 11 comprising axial portions, outer peripheral portion and cylindrical medial part in this reaction vessel 11 and the loading ratio of reductive agent, if total carbon is mol ratio to the ratio of the oxygen amount in ferric oxide in reductive agent, wish more than 1.1, more wish more than 1.15, preferably more than 1.2.

In addition, about the ferric oxide of above-mentioned cylindrical medial part and the Thickness ratio of reductive agent that raw material are filled to helical lay, when the ratio of the carbon amounts in reductive agent to the oxygen amount in ferric oxide is represented by mol ratio, wish more than 0.5.

[embodiment]

(embodiment 1)

In this embodiment, set each touchstone as shown in table 1, by the method being suitable for above-mentioned standard, oxide skin and reductant layer are filled in the reaction vessel 11 of SiC, carry out thick reduction treatment, manufactured sponge iron.Namely, the example that standard A ~ C and H in table is the fill method of round shape shown in Fig. 1, standard D ~ F replaces the example of fill method for the volution shown in Fig. 6, and standard G is the example that level replaces fill method.

Wherein the increasing amount 20% of so-called standard A, D loading level refers to that the thickness of the oxide skin of the rolling in reaction vessel 11 adds up to increase by 20%, the increasing amount 40% of so-called horizontal B, E loading level refers to that the thickness of the oxide skin of the rolling in reaction vessel 11 adds up to increase by 40%, and the increasing amount 60% of so-called horizontal C, F loading level refers to that the thickness of the oxide skin of the rolling in reaction vessel 11 adds up to increase by 60%.The detailed content of each condition is recorded in table 2.Under these conditions, each standard of filling is studied, have found fill method, applicable thickness and purity.

In this test, the ferric oxide of main raw material uses screening broken after the iron scale drying produced in hot-rolled process, obtains through adjustment the oxide skin powder (confirming that median size is between 0.05mm ~ 10mm) being accounted for the rolling of 40 quality % by the particle of 60 μm of sieve apertures.In addition, the reductive agent of auxiliary material uses the mixture of limestone powder and carbonaceous powder.Carbonaceous powder is coke and hard coal to use after the ratio mixing of about 7: 3, and coke uses median size to be the coke of 85 μm, and hard coal uses the hard coal that median size is 2.4mm.In addition, the limestone powder that relative reduction agent powder is the median size 80 μm of about 14 quality % is added.

Reaction vessel is the cylindrical vessel of internal diameter 400mm, when round shape is filled, fills iron oxide layer, is filled to the round shape of each numerical value, highly (axis) about 1500mm that external diameter is 320mm, thickness is table 2.When volution is filled, form the reductant layer that axial portions diameter is about 80mm, the thickness of outer peripheral portion is about 15mm, remaining cylindrical medial part carries out turn of the screw filling by table 2, is filled into height (axis) about 1500mm.More than more than 1.2 and 0.5 are respectively with the carbon amounts/oxygen amount (mol ratio) of cylindrical medial part in container.

Table 1

Level	Fill method	The increasing amount of loading level	Filling time	Filling work procedure
					A	Round shape is filled	20％	45 minutes	Continuously
B	Round shape is filled	40％	45 minutes	Continuously
					C	Round shape is filled	60％	45 minutes	Continuously
D	Turn of the screw is filled	20％	35 minutes	Continuously
					E	Turn of the screw is filled	40％	35 minutes	Continuously
F	Turn of the screw is filled	60％	35 minutes	Continuously
					G	Level is alternately filled	0％	90 minutes	Intermittently
H	Round shape is filled	0％	45 minutes	Continuously

Table 2

It is to confirm what the object of charging efficiency was carried out that level is alternately filled.Namely, use and alternately fill identical device for charging material with volution, only fill any one in croci and reductive agent powder, make rotation load cylinder to rotate simultaneously, after this is rotated the lifting of loading cylinder, use the same method and fill another kind of powder, repeatedly implement the operation of said sequence.As shown in table 1, level replaces filling and can not fill continuously, fill with round shape, turn of the screw fill compared with the filling time long.When turn of the screw is filled, the filling time can contract the shortest.

Each reaction vessel 11 being filled with raw material by each touchstone is placed on same chassis, loads continuous tunnel furnace.The chassis loaded approximately passed through preheat zone (200 DEG C ~ 900 DEG C) with 1 day time, with about 3 day time by sintering zone (1150 DEG C).After this about passed through cooling zone (200 DEG C ~ 900 DEG C) with 1 day time, chassis is come out of the stove from continuous tunnel furnace, more from container sponge iron is taken out, determine its purity.In addition, all sponge iron weight is all at more than 200kg.

The chemical composition that the purity of sponge iron utilizes oxygen analytical method to obtain, the content being converted into metallic iron is obtained.The results are shown in Figure 13.

As shown in figure 13, when turn of the screw fills (shade line), find the thickness of iron oxide layer until 60mm reduction is good, namely productivity increasing amount is good to 40% reduction, obtain the high purity sponge iron of purity more than 97 quality % or 98 quality %, productivity can be made to increase 40% of prior art by adjustment thickness.When round shape is filled on the other hand, to boost productivity 20% for target, thickness will reach the thick of 75mm, and purity is also 95.65 quality %, and the raising of productivity can not reach the degree of turn of the screw filling.

(embodiment 2)

Sponge iron has been manufactured by the method for following example 1 ~ 5 and conventional example 1.In addition, filling mode actual employing Fig. 3 A, carbon amounts/oxygen amount (mol ratio) is more than 1.2.

[example 1]

In this embodiment, to make that ferric oxide thickness is 50mm, the thickness rate such as reductive agent thickness is 50mm, turn of the screw is filled in reaction vessel.The reaction vessel used is height 1.8m, the cylindrical vessel of internal diameter 40cm.Reductive agent powder is used in the mixture that particle diameter mixes the Wingdale (median size about 95 μm) of 16 quality % in the coke powder of below 1mm.In addition, croci uses the oxide skin of the rolling being crushed to below 0.1mm (grinding and sieving obtains accounting for 40 quality % by the particle of 60 μm of sieve apertures through adjustment).The oxide skin powder of rolling, coke powder mean diameter are all within the scope of 0.05mm ~ 10mm.

Device for charging material uses the device for charging material shown in Fig. 4 A, the open height of croci relief outlet 15 is adjusted to 50mm, the open height of reductive agent powder discharge port 16 is adjusted to 50mm, to rotate the speed of rotation of loading cylinder 14b for per minute 4 turns, lift velocity is fill for 400mm/ minute.

The result of filling, obtains the 17 turn of the screw packing layers enclosed of ferric oxide thickness 50mm, solid reductant thickness 50mm.The loading level of ferric oxide is now 339kg.

[example 2]

In this embodiment, to make that ferric oxide thickness is 35mm, the thickness rate such as reductive agent thickness is 65mm, turn of the screw is filled in reaction vessel.Use reaction vessel, raw material powder and the device for charging material identical with example 1, fill ferric oxide and solid reductant.The open height of croci relief outlet 15 is adjusted to 35mm, the open height of reductive agent powder discharge port 16 is adjusted to 65mm, to rotate the speed of rotation of loading cylinder 14b for per minute 4 turns, lift velocity is fill for 400mm/ minute.

The result of filling, obtains the 17 turn of the screw packing layers enclosed of ferric oxide thickness 35mm, solid reductant thickness 65mm.The loading level of ferric oxide is now 237kg.

[example 3]

In this embodiment, be make that ferric oxide thickness is 60mm, the thickness rate such as reductive agent thickness is 40mm, turn of the screw is filled in the example in reaction vessel.Use reaction vessel, raw material powder and the device for charging material identical with example 1, fill ferric oxide and reductive agent.The open height of croci relief outlet 15 is adjusted to 60mm, the open height of reductive agent powder discharge port 16 is adjusted to 40mm, to rotate the speed of rotation of loading cylinder 14b for per minute 4 turns, lift velocity is fill for 400mm/ minute.

The result of filling, obtains the 17 turn of the screw packing layers enclosed of ferric oxide thickness 60mm, solid reductant thickness 50mm.The loading level of ferric oxide is now 406kg.

[example 4]

In this embodiment, be make that ferric oxide thickness is 25mm, the thickness rate such as reductive agent thickness is 25mm, turn of the screw is filled in the example in reaction vessel.Reaction vessel, raw material powder and the device for charging material identical with example 1 is used to fill ferric oxide and reductive agent.The open height of croci relief outlet 15 is adjusted to 25mm, the open height of reductive agent powder discharge port 16 is adjusted to 25mm, to rotate the speed of rotation of loading cylinder 14b for per minute 4 turns, lift velocity is fill for 200mm/ minute.

The result of filling obtains the 34 turn of the screw packing layers enclosed of ferric oxide thickness 25mm, solid reductant thickness 25mm.The loading level of ferric oxide is now 339kg.

[example 5]

In this embodiment, be make that ferric oxide thickness is 57.5mm, reductive agent thickness is filled in example in reaction vessel for 50mm.Use reaction vessel, raw material powder and the device for charging material identical with example 1, fill ferric oxide and reductive agent.The open height of croci relief outlet 15 is adjusted to 57.5mm, the open height of reductive agent powder discharge port 16 is adjusted to 50mm, to rotate the speed of rotation of loading cylinder 14b for per minute 4 turns, lift velocity is fill for 430mm/ minute.

The result of filling, obtains the 16 turn of the screw packing layers enclosed of ferric oxide thickness 57.5mm, solid reductant thickness 50mm.The loading level of ferric oxide is now 366kg.

[conventional example 1]

This example is the example that existing method according to Fig. 1 carries out round shape filling, use reaction vessel same as Example 1, form the round shape croci layer of thickness 57.5mm, external diameter φ 310mm, around this iron oxide layer, (comprise cylinder interior) fills reductive agent powder simultaneously.Use the reaction vessel identical with example 1 and raw material powder.Carbon amounts/oxygen amount (mol ratio) in container is about 2.2.

Reduction treatment uses continuous tunnel furnace to carry out, and has investigated the time required for reduction.

Above-mentioned result is gathered and is shown in table 3.

Wherein, the time required for so-called reduction refers to, in order to the time that the sponge iron obtaining purity more than 95% keeps at sintering zone (1150 DEG C).In addition, the time required for productivity reduction of so-called unit time removes the value of the ferric oxide weight loaded.

From the results shown in Table 3, the inventive method situation compared with the conventional method, can productivity be increased substantially.

Table 3

(embodiment 3)

[example 6]

Be used in the device for charging material shown in Fig. 4 A, bottom reaction vessel 11, pile up 30mm thick reductive agent powder 13 (coke powder).Upwards pressing by making the rotation with croci relief outlet 15 and reductive agent powder discharge port 16 load rotation limit, cylinder 14b limit order on it, in reaction vessel, being filled to the croci 12 (oxide skin of rolling) of thickness 40mm and the reductive agent powder 13 of thickness 50mm continuously with volution over-over mode.Finally, reductive agent powder (coke powder) 13 is filled in the upper end of reaction vessel 11.Utilize such filling, the mol ratio of the carbon amounts in reductive agent and the oxygen amount in ferric oxide is 1.6.Condition is in addition to the foregoing identical with embodiment 2.

[comparative example]

The horizontal filling mode shown in Fig. 8 is used to carry out same filling.The to-fill procedure of this example be first in the device for charging material 14 of Fig. 4 A at the reductive agent powder (coke powder) 13 that the underfill 50mm of reaction vessel 11 is thick, then unload on it and pile up the thick croci of 40mm (oxide skin of rolling) 12, repeatedly filling until the upper end of reaction vessel 1 with such to-fill procedure.Reductive agent powder (coke powder) 13 is filled in the upper end of reaction vessel 11.Utilize such filling, the mol ratio of the carbon amounts in reductive agent and the oxygen amount in ferric oxide is 1.6.

[conventional example 2]

Round shape filling mode shown in Figure 1A, B is used to carry out same filling.Except making carbon amounts/oxygen amount (mol ratio) be except 2.5, condition is identical with the conventional example 1 of embodiment 2.

Then, the reaction vessel 11 of the above-mentioned refractory materials being filled with raw material is placed on chassis, utilizes and make it carry out heating, the reduction of ferric oxide by continuous tunnel furnace.The continuous tunnel furnace total length 100m used, wherein the atmosphere temperature in the 40m region of middle part is adjusted to 1150 DEG C.In such a situa-tion, the ratio carrying out manufacturing iron is the operation of the sponge iron of 97 quality %, and its result summary sheet shows in table 4.

As can be seen from Table 4, in an embodiment of the present invention, machine speed is 1.3m/hr, compared with the 1.1m/hr of conventional example soon 18%.The oxide skin amount of the rolling of filling is 256kg/ container, adds 16% compared with the 220kg of conventional example.Its result, productivity improves 38%.Moreover, the heat of the unit mass sponge iron that heating needs can be reduced to 8820MJ/ton from 11470MJ/ton, decreases about 30%.

Table 4

	Example 6	Comparative example 1	Conventional example 2
				Filling mode	Volution is alternately filled	Level is alternately filled	Round shape is filled
Machine speed (m/h)	1.3	1.3	1.1
				The oxide skin loading level (kg/ container) of rolling	256	256	220
1150 DEG C of hold-times (h)	30.8	30.8	36.4
				Units of heat (MJ/ton)	8820	8820	11470

(embodiment 4)

Use the device for charging material shown in Fig. 5, manufacture sponge iron.The raw material used is identical with embodiment 2.Draw off part 14c for semicircle (central angle be about 180 ° fan-shaped).Use the reaction vessel of internal diameter 400mm, high 2000mm, the bossing (maximum height is about 20mm) that the reaction generation slag of melting attachment causes does not remove intentionally, inserts to rotate to load cylinder.Rotate that the profile loading cylinder main body is 310mm (77.5% of inside diameter of vessel), to draw off imaginary circular diameter in the plane section of part be 360mm (90% of inside diameter of vessel).

Load the front end of cylinder contact gently with reaction vessel even if rotate with above-mentioned bossing, can move to opposite side, so can the inserting without any problems bottom of reaction vessel, the insertion of raw material powder is not problem.The croci (ferric oxide thickness: 50mm, reductive agent thickness: 30mm) of 260kg can be filled without any problems in reaction vessel.

After filling, carry out the reduction identical with embodiment 2 with continuous tunnel furnace, there is no special problem, the spiral sponge iron blocks of more than purity 95 quality % can be obtained.

(embodiment 5)

The method of following example 7 ~ 11, comparative example 2 and conventional example 3 is utilized to manufacture sponge iron.Filling mode presses Fig. 6.

In this embodiment, the croci of main raw material uses oxide skin and the iron ore of rolling, suitably broken and adjustment granularity.Reductive agent powder be from coke powder, charcoal, coal dust, wood charcoal powder etc. separately or in mixture the material of wantonly more than a kind carry out suitably fragmentation and use after adjusting granularity.Make median size all within the scope of 70 μm ~ 90 μm.

Use the device that there is the rotation shown in Figure 14 and load cylinder, upon commencement of operations, first reductive agent powder 13 is laid in the bottom of reaction vessel 11, make the rotation of device for charging material 14 load cylinder 14b to rotate, promote with certain speed simultaneously, helically replaces shape and croci 12 and reductive agent powder 13 is contained in above it, is performed until the upper end of reaction vessel 11.And covering reductive agent powder 13 is filled at the top in reaction vessel 11.In order to take out goods (sponge iron) and prevent sponge iron to be attached on container, and in order to improve the diffuser efficiency of reactant gases, the outer peripheral portion near axial portions and wall of container only fills reductive agent.

[conventional example 3]

This example is the existing fill method shown in Fig. 1.In the reaction vessel 1 (internal diameter 400mm, length 1800mm) of refractory materials, namely fill the iron oxide layer (but other position is reductive agent) of external diameter 310mm internal diameter 200mm, length 1600mm.When making the carbon amounts/oxygen amount (mol ratio) in container be 2.2, aimed purity is the recovery time (1150 DEG C, following identical) of 97.0mass% is 53 hours.

[example 7]

In this instance, adopt volution to replace filling mode, make ferric oxide be the volution of external diameter 390mm, internal diameter 60mm, thickness 60mm, make reductive agent be thickness 45mm, all the other identical volutions, both fill simultaneously.Be 0.8 at the ferric oxide of cylindrical medial part and the carbon amounts/oxygen amount (mol ratio) of reductive agent, the carbon amounts/oxygen amount (mol ratio) in whole filling raw material is 1.2.In this instance, first, loading level adds 35% than conventional example 3, and the recovery time stopped by 60 hours.Sponge iron is attached to the inner face of container, can take out easily.

[example 8]

In this instance, adopt volution to replace filling mode, make ferric oxide be the volution of external diameter 365mm, internal diameter 100mm, thickness 60mm, make reductive agent be thickness 28mm, all the other identical volutions, both fill simultaneously.Being 0.5 at the ferric oxide of cylindrical medial part and the carbon amounts/oxygen amount (mol ratio) of reductive agent, is 1.2 to the mol ratio of whole filling.In this instance, first, loading level adds 35% than conventional example 3, and the recovery time stopped by 59 hours.Sponge iron is attached to the inner face of container, can take out easily.

[example 9]

In this instance, adopt volution to replace filling mode, make ferric oxide be the volution of external diameter 350mm, internal diameter 100mm, thickness 60mm, make reductive agent be thickness 17mm, all the other identical volutions, both fill simultaneously.Being 0.3 at the ferric oxide of cylindrical medial part and the carbon amounts/oxygen amount (mol ratio) of reductive agent, is 1.2 to the mol ratio of whole filling.In this instance, first, loading level adds 35% than conventional example 1, and the recovery time has used 70 hours.Sponge iron is attached to the inner face of container, can take out easily.But even if consider increase yield share, the recovery time is also equal degree with existing method 3.

[example 10]

In this instance, adopt volution to replace filling mode, make ferric oxide be the volution of external diameter 375mm, internal diameter 100mm, thickness 60mm, make reductive agent be thickness 45mm, all the other identical volutions, both fill simultaneously.Being 0.8 at the ferric oxide of cylindrical medial part and the carbon amounts/oxygen amount (mol ratio) of reductive agent, is 1.5 to the mol ratio of whole filling.In this instance, first, loading level adds 20% than conventional example 3, and the recovery time stopped by 59 hours.Sponge iron is attached to the inner face of container, can take out easily.In container, the productivity of the example 7 unit reduction time that carbon amounts/oxygen amount (mol ratio) is low is high, even this example also obtains result more better than existing method.

[example 11]

In this instance, adopt volution to replace filling mode, make ferric oxide be the volution of external diameter 395mm, internal diameter 40mm, thickness 60mm, make reductive agent be thickness 45mm, all the other identical volutions, both fill simultaneously.Being 0.8 at the ferric oxide of cylindrical medial part and the carbon amounts/oxygen amount (mol ratio) of reductive agent, is 1.1 to the mol ratio of whole filling.Loading level adds 40% than conventional example 3, and the recovery time has used 78 hours.Sponge iron is attached to the inner face of container, can take out easily.In this instance, the recovery time extends slightly, even if consider increase yield share, the recovery time is also equal degree with existing method 3.

Above result summary sheet shows in table 5.

Table 5

*) ferric oxide weight (relative ratio)/recovery time (h)

The possibility that industry utilizes

As described above, adopting words of the present invention, by adopting volution to replace filling technique, sponge iron can be produced on the basis of guaranteeing high productivity and high quality (such as purity is more than 97%).And, owing to can arbitrarily, easily and promptly change the formation of filling raw material in reaction vessel, so easily adjust quality, output, recovery time etc., can realize productivity is significantly improved.And then marked down manufacture highly purified sponge iron.

Claims

1. a charging apparatus for sponge iron production of raw material for use, namely enters croci and reductive agent powder with the charging apparatus making it be piled into the layer of interlaced and helically at container content, has

Be inserted in described container, can rotate in container and the insertion portion moved up and down and

Be arranged on the end portion of described insertion portion, the croci relief outlet that can rotate together with described insertion portion and reductive agent powder discharge port.

2. the charging apparatus of a sponge iron production of raw material for use, namely croci and reductive agent powder is entered at container content, the layer be made up of reductive agent powder is formed to make the container side in the described reaction vessel being called as outer peripheral portion and vertical centre shaft portion, simultaneously described croci and described reductive agent powder are piled into the charging apparatus of the layer of interlaced and helically at the middle portion as the rest part except this layer, have

Be arranged on the end portion of described insertion portion, the croci relief outlet that can rotate together with described insertion portion and the reductive agent powder discharge port of middle portion, and

Described load part bottom surface, axis of rotation position, with described middle portion with reductive agent powder discharge port be connected or be provided with the reductive agent powder discharge port of vertical centre shaft portion independently,

Further, described load part side, with described middle portion with reductive agent powder discharge port be connected or be provided with the reductive agent powder discharge port of outer peripheral portion independently.

3. the charging apparatus of sponge iron production of raw material for use as claimed in claim 1 or 2, the port area of described croci relief outlet and described reductive agent powder discharge port can change.

4. the charging apparatus of sponge iron production of raw material for use as claimed in claim 1 or 2, described insertion portion, has

Diameter be less than 85% of described inside diameter of vessel cylindrical-shaped main body part and

The horizontal section shape being 90 ~ 95% of described inside diameter of vessel by diameter is the end portion that a part for the cylinder of circle is formed, and

The horizontal section shape of described end portion is the fan-shaped of center containing described circle and part-circular periphery, or comprises this fan-shaped shape.